: any of an order (Testudines syn. Chelonia) of terrestrial, freshwater, and marine reptiles that have a toothless horny beak and a shell of bony dermal plates usually covered with horny shields enclosing the trunk and into which the head, limbs, and tail usually may be withdrawn

ETYMOLOGY:

modification of French tortue, from Late Latin (bestia) tartarucha, feminine of tartaruchus of Tartarus, from Greek tartarouchos, from Tartaros Tartarus; from Mithraic and early Christian association of the turtle with infernal forces